NEST by Elastic and contributors

<PackageReference Include="NEST" Version="6.0.0-beta1" />

.NET API 4,892,160 bytes

 GeoIpProcessor

public class GeoIpProcessor : ProcessorBase, IGeoIpProcessor, IProcessor
The GeoIP processor adds information about the geographical location of IP addresses, based on data from the Maxmind databases. This processor adds this information by default under the geoip field. The geoip processor can resolve both IPv4 and IPv6 addresses.
public string DatabaseFile { get; set; }

public Field Field { get; set; }

public bool? IgnoreMissing { get; set; }

If `true` and `field` does not exist, the processor quietly exits without modifying the document

public IEnumerable<string> Properties { get; set; }

public Field TargetField { get; set; }

public GeoIpProcessor()